1. Field of the Invention
The present invention relates to an image recording apparatus configured to convey a sheet along a conveyance path and record an image on the sheet.
2. Description of the Related Art
There is conventionally known an image recording apparatus configured to record an image on a sheet. Examples of such an image recording apparatus include an ink jet image recording apparatus and an electrophotographic image recording apparatus.
To satisfy recent demand for reducing size and cost of an image recording apparatus, the number of motors provided in the image recording apparatus is preferably reduced. For example, there is known an image recording apparatus that includes: a drive gear to which a driving power is transmitted from a motor; and a switch gear slidable in thrust directions of the drive gear while meshed with the drive gear. In this image recording apparatus, a plurality of transmission gears for transmitting the power to various mechanisms are arranged respectively corresponding to slide positions of the switch gear. The switch gear is slidable and meshable selectively with one of the transmission gears. A power transmission switching mechanism having this construction reduces the number of motors provided in the image recording apparatus.
In this power transmission switching mechanism, when the switch gear is slid and newly meshed with one of the transmission gears, the motor needs to repeatedly perform forward and reverse rotation by a small rotational amount. As a result, the switch gear is smoothly meshed with the transmission gear.
Also, many recent image recording apparatuses have a duplex image recording function. For example, there is an image recording apparatus having a resupply conveyance path in addition to a main conveyance path for conveying a sheet from a supply tray to an output opening via a recording portion for recording an image on the sheet. The resupply conveyance path is a path through which a sheet with an image recorded on its front face by the recording portion is conveyed from a position downstream of the recording portion in a sheet conveying direction, to a position upstream of the recording portion in the sheet conveying direction in the main conveyance path.
In this image recording apparatus, a roller rotatable forwardly and reversely is provided downstream of the recording portion. This roller is rotated forwardly to discharge the sheet through the output opening and rotated reversely to guide the sheet to the resupply conveyance path. Also, a sensor is disposed between the recording portion and the roller in the main conveyance path. A timing when the rotation of the roller is switched from the forward rotation to the reverse rotation for guiding the sheet to the resupply conveyance path is determined on the basis of a timing when the sensor senses the conveyed sheet.